Category: Frege
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Kenny, Geach, and the Perils of Reading Frege Back Into Aquinas
London Ed has informed me of the passing of Peter Geach. May he find the Unchanging Light that he sought through his long and productive life of truth-seeking in these shadowlands. One honors a thinker best by thinking his thoughts, sympathetically, but critically. Here is one of my attempts. Others referenced below. ………… I have…
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Stanislav Sousedik’s “Towards a Thomistic Theory of Predication”
Enough of politics, back to some hard-core technical philosophy. If nothing else, the latter offers exquisite escapist pleasures not unlike those of chess. Of course I don't believe that technical philosophy is escapist; my point is a conditional one: if it is, its pleasures suffice to justify it as a form of recuperation from this all-too-oppressive world of…
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Aquinas Meets Frege: Analysis of an Argument from De Ente et Essentia
The other day I expressed my reservations as to the coherence of the Thomistic notion of a common nature. Let's plunge a little deeper by considering the argument from Chapter 3 of Thomas Aquinas, On Being and Essence (tr. Robert T. Miller, emphasis added): The nature, however, or the essence thus understood can be considered in two…
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Still Trying to Understand Van Inwagen’s Half-Way Fregeanism about Existence
In section 53 of The Foundations of Arithmetic, Gottlob Frege famously maintains that . . . existence is analogous to number. Affirmation of existence is in fact nothing but denial of the number nought. Because existence is a property of concepts the ontological argument for the existence of God breaks down. (65) Frege is here advancing…
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Existence and Plural Predication: Could ‘Exist(s)’ be a First-Level Non-Distributive Predicate?
'Horses exist' is an example of an affirmative general existential sentence. What is the status of the predicate '___ exist' in such a sentence? One might maintain that 'exist(s)' is a second-level predicate; one might maintain that it is a first-level distributive predicate; one might maintain that it is a first-level non-distributive (collective) predicate. 1. Frege famously maintained…
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More on Translating ‘Something Exists’ and a Response to Brightly
I issued the following challenge: translate 'Something exists' into standard first-order predicate logic with identity. This is the logic whose sources are Frege and Russell. So I call it Frege-Russell logic, or, to be cute, 'Fressellian' logic. My esteemed commenters don''t see much of a problem here. So let me first try to explain why…
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On Translating ‘Some Individual Exists’ Fressellianly
An astute reader comments: You write: 2. But can this presupposition be expressed (said) in this logic? Here is a little challenge for you Fressellians: translate 'Something exists' into standard logical notion. You will discover that it cannot be done. Briefly, if existence is instantiation, which property is it whose instantiation is the existence of…
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Transitivity of Predication?
I dedicate this post to London Ed, who likes sophisms and scholastic arcana. Consider these two syllogistic arguments: A1. Man is an animal; Socrates is a man; ergo, Socrates is an animal.A2. Man is a species; Socrates is a man; ergo, Socrates is a species. The first argument is valid. On one way of accounting for its…
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Frege Meets Aquinas: A Passage from De Ente et Essentia
Here is a passage from Chapter 3 of Thomas Aquinas, On Being and Essence (tr. Robert T. Miller, emphasis added): The nature, however, or the essence thus understood can be considered in two ways. First, we can consider it according to its proper notion, and this is to consider it absolutely. In this way, nothing is…
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Kenny, Geach, and the Perils of Reading Frege Back Into Aquinas
I have been studying Anthony Kenny, Aquinas on Being (Oxford 2002). I cannot report that I find it particularly illuminating. I am troubled by the reading back of Fregean doctrines into Aquinas, in particular in the appendix, "Frege and Aquinas on Existence and Number." (pp. 195-204) Since Kenny borrows heavily from Peter Geach, I will…
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Morning Star and Evening Star
London Ed of Beyond Necessity does a good job patiently explaining the 'morning star' – 'evening star' example to one of his uncomprehending readers. But I don't think Ed gets it exactly right. I quibble with the following: Summarising:(1) The sentence “the morning star is the evening star” has informational content.(2) The sentence “the morning star…
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The Difference Between a Truth-Bearer and a Truth-Maker
Frege makes the point that the being of a proposition cannot be identical to its being true. This I find obvious. There are true propositions and there are false propositions. Therefore, for propositions (the senses of context-free declarative sentences) it cannot be the case that to be = to be true. Furthermore, a given proposition that…
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Frege’s Regress
Some of us of a realist persuasion hold that at least some truths have need of worldly correlates that 'make them true.' This notion that (some) truths need truthmakers is a variation on the ancient theme that truth implies a correspondence of what-is said or what-is-thought with what-is. You all know the passages in Aristotle where…
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Atomic Sentences and Syncategorematic Elements
According to Fred Sommers (The Logic of Natural Language, p. 166), ". . . one way of saying what an atomic sentence is is to say that it is the kind of sentence that contains only categorematic expressions." Earlier in the same book, Sommers says this: In Frege, the distinction between subjects and predicates is not…
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Nota Notae Est Nota Rei Ipsius and the Ontological Argument
(By popular demand, I repost the following old Powerblogs entry.) "The mark of a mark is a mark of the thing itself." I found this piece of scholasticism in C. S. Peirce. (Justus Buchler, ed., Philosophical Writings of Peirce, p. 133) It is an example of what Peirce calls a 'leading principle.' Let's say you…